Clutch slipping

it also cracked the bell housing.

had the engine and bell housing replaced.
now the clutch slips
if some motor oil got on the clutch how long would it take to burn off?
if the slave cylinder got a bit of air in the line, would that cause the clutch to slip?
thanks,
max
it was working ok after i had the clutch replaced before i detonated the engine.
probably no more miles than 300 between the new clutch and new engine.
they took parts of the old engine and put on the replacement.
what is the proper break in procedure.





